Battery Thermal Management System

ABSTRACT

In certain embodiments, a battery thermal management system includes at least one battery, at least one thermoelectric device in thermal communication with the at least one battery, and a conduit comprising an inlet configured to allow a working fluid to enter and flow into the conduit and into thermal communication with the at least one thermoelectric device. The conduit further comprises an outlet configured to allow the working fluid to exit and flow from the conduit and away from being in thermal communication with the at least one thermoelectric device. The battery thermal management system can further include a first flow control device which directs the working fluid through the inlet of the conduit and a second flow control device which directs the working fluid through the outlet of the conduit. The first flow control device and the second flow control device are each separately operable from one another.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/782,532 filed May 18, 2010, which claims the benefit of U.S.Provisional application No. 61/179,326 filed May 18, 2009, each of whichis incorporated herein in its entirety by reference.

BACKGROUND

1. Field of the Invention

The present application relates to battery thermal management systemsand thermoelectric cooling and heating batteries.

2. Description of the Related Art

High performance batteries for use in large systems (including, forexample, lithium based batteries used in electrical vehicles) havecertain properties that make thermal management of the batteries and/orcontainment system desirable. Charging characteristics of highperformance batteries change at elevated temperatures and can cause thecycle life of the batteries to decrease significantly if they arecharged at too high of a temperature. For example, the cycle life ofsome lithium based batteries decreased by over 50% if they arerepeatedly charged at about 50° C. Since cycle life can be reduced by alarge amount, the lifetime cost of batteries can be greatly increased ifcharging temperatures are not controlled within proper limits. Also,some high performance batteries can exhibit reduced performance and canbe possibly damaged if charged or operated at too low of temperatures,such as below about −30° C. Furthermore, high performance batteries andarrays of high performance batteries can experience thermal events fromwhich the batteries can be permanently damaged or destroyed, and overtemperature condition can even result in fires and other safety relatedevents.

SUMMARY

In certain embodiments, a battery thermal management system is provided.The battery thermal management system can include at least one batteryand a plurality of thermoelectric assemblies in thermal communicationwith the at least one battery. Each thermoelectric assembly can includea plurality of thermoelectric elements, and a first thermoelectricassembly of the plurality of thermoelectric assemblies is in electricalcommunication with a second thermoelectric assembly of the plurality ofthermoelectric assemblies. The battery thermal management system canalso include a circuit in electrical communication with the firstthermoelectric assembly and the second thermoelectric assembly. Thecircuit can be configured to be selectively switchable to place thefirst thermoelectric assembly and the second thermoelectric assemblyeither in series electrical communication or parallel electricalcommunication with one another.

In some embodiments, the at least some of the plurality ofthermoelectric elements of the first thermoelectric assembly are inseries electrical communication with one another and at least some ofthe plurality of thermoelectric elements of the second thermoelectricassembly are in series electrical communication with one another. Infurther embodiments, the plurality of thermoelectric assemblies areselectively operable to either heat or cool the at least one battery.

In certain embodiments, a method of thermally managing a battery systemincludes providing a battery system comprising at least one battery anda plurality of thermoelectric assemblies in thermal communication withthe at least one battery. The method can further include measuring atleast one parameter of the battery system and switching, in response tothe at least one parameter, a first thermoelectric assembly of theplurality of thermoelectric assemblies between being in parallel or inseries electrical communication with a second thermoelectric assembly ofthe plurality of thermoelectric assemblies. In some embodiments the atleast one parameter is a temperature of the at least one battery and/ora temperature of the plurality of thermoelectric assemblies.

In certain embodiments, a battery thermal management system includes atleast one battery, at least one thermoelectric device in thermalcommunication with the at least one battery, and at least one firstconduit comprising at least one inlet configured to allow a firstworking fluid to enter and flow into the at least one first conduit andinto thermal communication with the at least one thermoelectric device.The at least one first conduit further comprises at least one outletconfigured to allow the first working fluid to exit and flow from the atleast one first conduit and away from being in thermal communicationwith the at least one thermoelectric device. The battery thermalmanagement system can further include at least one first flow controldevice which directs the first working fluid through the at least oneinlet of the at least one first conduit and at least one second flowcontrol device which directs the first working fluid through the atleast one outlet of the at least one first conduit. The at least onefirst flow control device and the at least one second flow controldevice are each separately operable from one another.

In some embodiments, the at least one second conduit comprises at leastone inlet configured to allow a second working fluid to enter and flowinto the at least one second conduit and into thermal communication withthe at least one thermoelectric device. The at least one second conduitcomprises at least one outlet configured to allow the second workingfluid to exit and flow from the at least one second conduit and awayfrom being in thermal communication with the at least one thermoelectricdevice. The battery thermal management system can also include at leastone third flow control device which directs the second working fluidthrough the at least one inlet of the at least one second conduit and atleast one fourth flow control device which directs the second workingfluid through the at least one outlet of the at least one secondconduit. The at least third first flow control device and the at leastone fourth flow control device can each be separately operable from oneanother.

In certain embodiments, a method of thermally managing a battery systemincludes transferring heat between at least one battery and at least onethermoelectric device, and flowing a working fluid through a fluidconduit in thermal communication with the at least one thermoelectricdevice. The method can also include operating at least one first flowcontrol device to direct the working fluid to be in thermalcommunication with the at least one thermoelectric device, and operatingat least one second flow control device separately from the operating ofthe at least one first flow control device to direct the working fluidaway from being in thermal communication with the at least onethermoelectric device.

In certain embodiments, a battery thermal management system includes atleast one battery, at least one thermoelectric device in thermalcommunication with the at least one battery, and at least one fluidconduit configured to allow a working fluid to flow therein and totransfer the working fluid into being in thermal communication with theat least one thermoelectric device or away from being in thermalcommunication with the at least one thermoelectric device. The batterythermal management system can further include at least one first flowcontrol device which directs the working fluid through the at least onefluid conduit and at least one second flow control device which directsthe working fluid through the at least one fluid conduit. The at leastone first flow control device and the at least one second flow controldevice are each separately operable from one another. The batterythermal management system can also include at least one divider portionthat is selectively positionable to block the working fluid from flowingbetween the at least one fluid conduit and a selected one of the atleast one first flow control device and the at least one second flowcontrol device.

In certain embodiments, a method of thermally managing a battery systemincludes transferring heat between at least one battery and at least onethermoelectric device, and flowing a working fluid through a fluidconduit in thermal communication with at least one thermoelectricdevice. The method can further include directing the working fluidthrough the fluid conduit using at least one first flow control deviceand at least one second flow control device, and selectively inhibitingflow of the working fluid through a selected one of the at least onefirst flow control device and the at least one second flow controldevice.

In certain embodiments, a method of thermally managing a battery systemincludes providing a battery system comprising at least one battery anda plurality of thermoelectric devices in thermal communication with theat least one battery. The plurality of thermoelectric devices comprise afirst group of one or more thermoelectric devices in series electricalcommunication with a second group of one or more thermoelectric devices.The method can further include measuring a first electrical voltage orcurrent of the first group, measuring a second electrical voltage orcurrent of the second group or of both the first group and the secondgroup together, and monitoring an electrical comparison parameterdependent on the first electrical voltage or current and the secondelectrical voltage or current.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic circuit diagram of an example thermal managementsystem including a plurality of TE devices in accordance with certainembodiments described herein;

FIG. 2 is an illustrative plot of operating electrical current as afunction of the efficiency of energy conversion (COP) and the totalthermal output of a TE device;

FIG. 3 is a schematic circuit diagram of an example thermal managementsystem including a plurality of TE devices and voltage meters inaccordance with certain embodiments described herein;

FIG. 4A is an example thermal management system illustrating flow of aworking fluid with flow control devices in series in accordance withcertain embodiments described herein;

FIG. 4B is an example thermal management system illustrating flow of aworking fluid with flow control devices in parallel in accordance withcertain embodiments described herein;

FIG. 5 is a schematic circuit diagram of an example thermal managementsystem that includes a control that can be configured to be selectivelyswitchable to place two thermoelectric assemblies either in serieselectrical communication or parallel electrical communication with oneanother in accordance with certain embodiments described herein;

FIG. 6 is an example thermal management system that includes monitoringsystems to measure at least one parameter in accordance with certainembodiments described herein; and

FIG. 7 is an example thermal management system that includes a fluidconduit loop in accordance with certain embodiments described herein.

DETAILED DESCRIPTION

Battery thermal management systems (BTMS) can be used to controltemperatures and monitor conditions of batteries and arrays of batteriesto prevent battery failure and/or safety related failure. A BTMS canimprove the overall conditions of battery operation by both managing thethermal environment and also being sufficiently reliable so that overallsystem performance is not degraded. For example, a BTMS may not reduceoverall system reliability and not increase system operating cost by notincluding significant additional possible failure mechanisms to thesystem. Furthermore, the systems can be environmentally friendly and notcontain materials that emit greenhouse gases such as refrigerants.

A BTMS includes at least one battery or battery array. In certainembodiments, a battery thermal management system can be used to bothheat and cool batteries and/or battery arrays. For example, the batterythermal management system can be integrated with the at least onebattery, the battery thermal management system can be integrated with anenclosure wherein the at least one battery is contained, or the thermalmanagement system can be positioned in thermal communication with the atleast one battery.

In certain embodiments, a battery thermal management system includes oneor more thermoelectric (TE) devices. For example, the battery thermalmanagement system can include a plurality of thermoelectric elements, atleast one thermoelectric assembly, and/or at least one thermoelectricmodule. TE devices are solid state and do not utilize refrigerants toproduce cooling, and some TE devices can produce both heating andcooling. Furthermore, battery thermal management systems can include aplurality of TE devices which can be configured to increase reliabilityover that of a conventional two phase refrigerant system, such as oneemploying refrigerant 134A.

A variety of embodiments of battery thermal management systems aredescribed below to illustrate various configurations. The particularembodiments and examples are only illustrative and features described inone embodiment or example may be combined with other features describedin other embodiments or examples. Accordingly, the particularembodiments and examples are not intended to be restrictive in any way.

Battery thermal management systems with improved thermoelectric devicereliability

In certain embodiments, a battery thermal management system 100 includesat least one battery and a plurality of thermoelectric devices inthermal communication with the at least one battery. FIG. 1 is aschematic circuit diagram of an example thermal management system 100comprising a plurality of TE devices in accordance with certainembodiments described herein. The TE devices can be TE elements, TEassemblies, and/or TE modules. The plurality of TE devices includes afirst group 104 a of TE devices and a second group 104 b of TE devices.The TE devices of the first TE group 104 a are in parallel electricalcommunication with one another, and the TE devices of the second TEgroup 104 b are in parallel electrical communication with one another.In particular, TE device 1, TE device 2, and TE device 3 are in parallelelectrical communication with one another and TE device 4, TE device 5,and TE device 6 are in parallel electrical communication with oneanother. The first TE group 104 a and the second TE group 104 b are inseries electrical communication with one another. One or more additionalTE groups 104 c can also be placed in series electrical communicationwith the first TE group 104 a and the second TE group 104 b.

The battery thermal management system 100 can improve overall systemcooling and heating reliability. First, the TE devices are configured soas to allow redundancy and eliminate common single point failuremechanisms within each TE group. For example, if TE device 1 fails opensuch that the TE device 1 is electrically open (e.g., the TE device isunable to pass electrical current), the current is rerouted through TEdevice 2 and TE device 3 which are electrically connected in parallelwith the failed TE device 1. If three or more TE devices areelectrically connected together in parallel, more than one TE devicecould fail open, and the thermal management system 100 would stilloperate to provide cooling and/or heating.

In a further example, if TE device 1 fails closed (e.g., the TE device 1is more electrically conductive than TE device 2 and TE device 3), moreof the electrical current will flow through the failed TE device 1 thanTE device 2 and TE device 3, and reduce or eliminate the cooling and/orheating of the TE device 2 and TE device 3 in the same parallelelectrical connection. The TE group 2 that is in series electricalcommunication with TE group 1 will continue to function and provideheating and/or cooling. Failure of a TE device will degrade performance,but with sufficient numbers of TE devices, and the proper operatingconditions, the thermal management system 100 can continue to function,albeit at a reduced heating and/or cooling capability if a TE devicefails. In arrays larger than illustrated in FIG. 1, performance of athermal management system 100 with one or more failed TE devices can besubstantially the same as that of a thermal management system 100without any failed TE devices. Further examples of TE device redundancyare described in U.S. Patent Publication No. 2010/0031987, which isincorporated herein in its entirety by reference.

FIG. 2 is a illustrative plot of operating electrical current as afunction of the efficiency of energy conversion (COP) and the totalthermal output of a TE device (Q_(c)). Points A and A′ are near theoperating current that optimizes operating efficiency of the TE device(indicated by Point A) so that it will operate near its peak possibleefficiency. Points B and B′ are a second operating current that is at1.5 times the operating current of Points A and A′, and Points C and C′are at a third operating current 3 times the operating current of PointsA and A′. The dashed lines in FIG. 2 illustrate positions of the pointsrelative to each other and relative to the x and y axes. If the TEdevice operates under a lower temperature differential, efficiency willbe lower at Points B, B′, C, and C′, but cooling and/or heating powerwill be diminished by a relatively small amount so that cooling and/orheating power will remain nearly the same. Furthermore, a TE device canhave a thermal output beyond peak operating efficiency by increasingelectrical power even though efficiency may decrease.

The change in the operating circuit induced by failure of one or more TEdevices can result in a different current-voltage relationship of abattery thermal management system 300. Thus, for example if one or moreTE devices fail, and if current to the battery thermal management system300 is fixed, a voltage change will be induced, and vice versa, ifvoltage is fixed, a current change will be induced. FIG. 3 is aschematic circuit diagram of an example thermal management system 300that includes a plurality of TE devices in accordance with certainembodiments described herein. The thermal management system 300 in FIG.3 also illustrates an example monitoring method to detect failure of aTE device. Diagnosing failure in a TE device of a thermal managementsystem 300 can be measured through monitoring voltages and/or currentsof the battery thermal management system 300, either under transient orquasi-steady state conditions. Many other monitoring methods are alsopossible.

The electrical configuration of the TE devices of the battery thermalmanagement system 300 illustrated in FIG. 3 is similar to thatillustrated in FIG. 1. The battery thermal management system 300includes a plurality of TE devices includes a first TE group 304 a and asecond TE group 304 b. The TE devices of the first TE group 304 a are inparallel electrical communication with one another, and the TE devicesof the second TE group 304 b are in parallel electrical communicationwith one another. In particular, TE device 1, TE device 2, and TE device3 are in parallel electrical communication with one another and TEdevice 4, TE device 5, and TE device 6 are in parallel electricalcommunication with one another. The first TE group 304 a and the secondTE group 304 b are in series electrical communication with one another.One or more additional TE groups 304 c can also be placed in serieselectrical communication with the first TE group 304 a and the second TEgroup 304 b.

In certain embodiments, a method of thermally managing a battery system300 includes providing a battery system comprising at least one batteryand a plurality of thermoelectric devices in thermal communication withthe at least one battery. The plurality of thermoelectric devicesincludes a first group 304 a of thermoelectric devices in serieselectrical communication with a second group 304 b of thermoelectricdevices. The method includes measuring a first electrical voltage orcurrent of the first group 304 a and measuring a second electricalvoltage or current of the second group 304 b or both the first group 304a and second group 304 b together. The method further includesmonitoring an electrical comparison parameter dependent on the firstelectrical voltage or current and the second electrical voltage orcurrent. In some embodiments, the electrical comparison parametercomprises a value of the first electrical voltage or current divided bythe second electrical voltage or current. In further embodiments, themethod further includes changing, in response to the electricalcomparison parameter, at least one parameter of the battery system. Theat least one parameter can be, for example, electrical power supplied tothe plurality of thermoelectric devices.

The thermal management system 300 can include two or more voltage and/orcurrent meters for measuring the electrical voltage or current. Forexample, a first meter 306 a can measure a first voltage and/or current(V₁) across the first group 304 a, and a second meter 306 b can measurea second voltage and/or current (V₂) across the second group 304 b. Asystem meter 302 can measure a system voltage and/or current (V⁺) acrossthe first TE group 304 a, the second group 304 b, and the one or moreadditional TE groups 304 c. The ratio of V₁/V₂, V₁/V⁺, or V₂/V⁺willchange if one or more TE devices fail. Furthermore, even if the systemvoltage or current (V+) changes, the ratios V₁/V₂, V₁/V⁺, and V₂/V⁺wouldremain constant if one or more TE devices does not fail. Therefore, bymonitoring V₁ and V₂ or V⁺, a failure of a TE device can be detected.

Battery thermal management system with improved working fluid flow andelectronics reliability

Other possible failure modes include those associated with a fluidcooling/heating system. For example, if more than one flow controldevice (e.g., fan or pump) is used to move a working fluid, reliabilitycan be increase over use of a single flow control device. FIG. 4Aillustrates an example battery thermal management system 400 inaccordance with certain embodiments described herein. In certainembodiments, a battery thermal management system 400 includes at leastone battery 402 a-d and at least one thermoelectric device 404 inthermal communication with the at least one battery 402 a-d.

The battery thermal management system 400 can include at least one firstconduit 406 that includes at least one inlet 408 configured to allow afirst working fluid to enter and flow into the at least one firstconduit 406 and into thermal communication with the at least onethermoelectric module 404. For example, a heat exchanger 428 cantransfer heat between the at least one thermoelectric module 404 and thefirst working fluid. The at least one first conduit 406 also includes atleast one outlet 410 configured to allow the first working fluid to exitand flow from the at least one first conduit 406 and away from being inthermal communication with the at least one thermoelectric module 404.The battery thermal management system 400 can further include at leastone first flow control device 412 which directs the first working fluidthrough the at least one inlet 408 of the at least one first conduit406, and at least one second flow control device 414 which directs thefirst working fluid through the at least one outlet 410 of the at leastone first conduit 406. The at least one first flow control device 412and the at least one second flow control device 414 are each separatelyoperable from one another. In certain embodiments, the at least onefirst flow control device 412 pushes the first working fluid while theat least one second flow control device 414 pulls the first workingfluid, and the at least one first flow control device 412 and the atleast one second flow control device 414 are in series with one anotheror are in a push/pull configuration. The arrows in FIG. 4A illustratethe direction of flow of the working fluid.

In some embodiments, the at least one first control device 412 ispositioned at an entrance of the at least one inlet 408 and the at leastone second control device 414 is positioned at an exit of the at leastone outlet 410. In further embodiments, the at least one first controldevice 412 is configured to push the first working fluid through the atleast one inlet 408 and the at least one second control device 414 isconfigured to pull the first working fluid through at least one outlet410. In certain embodiments, the battery thermal management system 400further includes a flow path for the first working fluid in which thefirst working fluid is in thermal communication with the at least onebattery. The flow path, in some embodiments, receives the first workingfluid from the at least one outlet 408. In other embodiments, the firstworking fluid is substantially thermally or electrically isolated fromthe at least one battery. For example, the thermoelectric module 404 caninclude two sides including a cooler side and a hotter side. The firstworking fluid can be in thermal communication with only the cooler sideor the hotter side, and the first working fluid can be substantiallythermally isolated from the other side.

In certain embodiments, the battery thermal management system 400includes at least one second conduit 416 including at least one inlet418 configured to allow a second working fluid to enter and flow intothe at least one second conduit 416 and into thermal communication withthe at least one thermoelectric device 404. For example, a heatexchanger 426 can transfer heat between the at least one thermoelectricdevice 404 and the second working fluid. The at least one second conduit416 includes at least one outlet 420 configured to allow the secondworking fluid to exit and flow from the at least one second conduit 416and away from being in thermal communication with the at least onethermoelectric device 404. The battery thermal management system 400includes at least one third flow control device 422 which directs thesecond working fluid through the at least one inlet 418 of the at leastone second conduit 416, and at least one fourth flow control device 424which directs the second working fluid through the at least one outlet420 of the at least one second conduit 416. The at least one third firstflow control device 422 and the at least one fourth flow control device424 are each separately operable from one another.

The arrows in FIG. 4A illustrate the direction of flow of the firstworking fluid and the second working fluid. In certain embodiments, thefirst working fluid is substantially thermally isolated from the secondworking fluid. For example, the first working fluid can be in thermalcommunication with a first side of the TE device 404 and the at leastone battery 402 a-d, and the second working fluid can be in thermalcommunication with a second side of the TE device 404 different from thefirst side. Furthermore, the at least one battery 402 a-d can beselectively heated or cooled and the first working fluid and secondworking fluid can be correspondingly heated or cooled. For example, thefirst side of the TE device 404 can be selected to heat or cool the atleast one battery 402 a-d by heating or cooling the first working fluidand transferring heat between the at least one battery 402 a-d and thefirst working fluid, and the second working fluid can be correspondinglycooled if the first working fluid is heated or heated if the firstworking fluid is cooled.

In certain embodiments, a method of thermally managing a battery thermalmanagement system 400 includes transferring heat between at least onebattery 402 a-d and at least one thermoelectric device 404 and flowing aworking fluid through a fluid conduit 406 in thermal communication withthe at least one thermoelectric device 404. The method further includesoperating at least one first flow control device 412 to direct theworking fluid to be in thermal communication with the at least onethermoelectric device 404 and operating at least one second flow controldevice 414 to direct the working fluid away from being in thermalcommunication with the at least one thermoelectric device 404. In someembodiments, the working fluid flows past, along, or around the at leastone battery 402 a-d and heat is transferred from or to the at least onebattery 402 a-d. In other embodiments, the at least one battery 402 a-dis in substantially direct thermal communication with the TE device 404and a working fluid does not transfer heat between the at least onebattery 402 a-d and the TE device. In some embodiments, the workingfluid is substantially thermally isolated from the at least one battery402 a-d and heat is transferred between the TE device 404 and workingfluid. For example, the working fluid can transfer waste heat away fromthe TE device 404.

FIG. 4B illustrates a fluid conduit 450 of a battery thermal managementsystem in accordance with certain embodiments described herein. Forcomparison, FIG. 4B is an example of flow control devices working inparallel while FIG. 4A is an example of flow control devices working inseries. In certain embodiments, a battery thermal management systemincludes at least one battery and at least one thermoelectric module 452in thermal communication with the at least one battery. The batterythermal management system further includes at least one fluid conduit450 configured to allow a working fluid to flow therein and to transferthe working fluid into being in thermal communication with the at leastone thermoelectric module 452 or away from being in thermalcommunication with the at least one thermoelectric module 452. At leastone first flow control device 454 directs the working fluid through theat least one fluid conduit 450, and at least one second flow controldevice 456 directs the working fluid through the at least one fluidconduit 450. The at least one first flow control device 454 and the atleast one second flow control device 456 are each separately operablefrom one another.

The battery thermal management system also includes at least one dividerportion 458 that is selectively positionable to block the working fluidfrom flowing between the at least one fluid conduit 450 and a selectedone of the at least one first flow control device 454 and the at leastone second flow control device 456. For example, a divider wall 460 canseparate the at least one fluid conduit 450, and a flapper valve 462 canbe positioned to block flow of the working fluid through either thefirst flow control device 454 or the at least one second flow controldevice 456. The dotted line in FIG. 4B illustrates the flapper valve 462blocking the flow through the at least one second flow control device456, and the arrow illustrates how the flapper valve 462 can rotate toblock the flow of the working fluid from flowing through the at leastone second flow control device 456. The flapper valve 462 prevents backflow of the working fluid through an inoperative flow control device.The other arrows in FIG. 4B illustrate the direction of flow of theworking fluid.

In certain embodiments, the at least one divider portion 458 ispositionable in multiple positions including: (1) a first positionpermitting the working fluid to flow between the at least one fluidconduit 450 and the at least one first flow control device 454 andpermitting the working fluid to flow between the at least one fluidconduit 450 and the at least one second flow control device 456, (2) asecond position permitting the working fluid to flow between the atleast one fluid conduit 450 and the at least one first flow controldevice 454 and blocking the working fluid from flowing between the atleast one fluid conduit 450 and the at least one second flow controldevice 456, and (3) a third position blocking the working fluid fromflowing between the at least one fluid conduit 450 and the at least onefirst flow control device 454 and permitting the working fluid to flowbetween the at least one fluid conduit 450 and the at least one secondflow control device 458.

In some embodiments, the battery thermal management system can includeboth flow control devices in series and parallel. For example, the atleast one first flow control device 412 in FIG. 4A can include at leasttwo first flow control devices. Furthermore, the battery thermalmanagement system 400 can include at least one divider portion that isselectively positionable to block the working fluid from flowing betweenthe at least one first fluid conduit 406 and a selected one of the atleast one first flow control devices 412. In certain embodiments, thedivider portion separates at least a portion of the at least one inletor the at least one outlet into at least two fluid channels comprising afirst fluid channel and a second fluid channel. At least one flowcontrol device of the at least two first flow control devices 412directs the first working fluid through a first fluid channel, and atleast one other flow control device of the at least two first flowcontrol devices directs the first working fluid through a second fluidchannel. Each of the at least two first flow control devices are eachseparately operable from one another.

In certain embodiments, a method of thermally managing a battery systemincludes transferring heat between at least one battery and at least onethermoelectric device 452 and flowing a working fluid through a fluidconduit 450 in thermal communication with at least one thermoelectricdevice 452. The method further includes directing the working fluidthrough the fluid conduit 450 using at least one first flow controldevice 454 and at least one second flow control device 456 andselectively inhibiting flow of the working fluid through a selected oneof the at least one first flow control device 454 and the at least onesecond flow control device 456.

The reliability of the electrical power provided by the BTMS can also beimproved. In certain embodiments, the battery thermal management systemincludes a plurality of power lines and/or redundancy with the powersource or supply. For example, the power supply can have several powerconversion phases and energy filtering and/or storage components. Othermethods of providing electrical power redundancy may also be provided.While performance such as ripple or drop out may occur as the result ofa single failure, cooling or heating can continue to be provided.

Thermal management systems

In certain embodiments, the TE device is put in close proximity to thebattery. For example, TE device may be attached, coupled, or integratedwith the battery or a battery case. To improve efficiency of the BTMS,increase heating and/or cooling capacity, and/or increase temperaturecontrol uniformity across a battery, the cooling or heating side of a TEdevice can be advantageously positioned as close to the battery aspossible. Furthermore, the cooling or heating power that may be lostthrough ducts or insulation can directly condition the system.Conditioning can include transferring heat to the battery to increasethe temperature of the battery or transferring heat from the battery todecrease the temperature of the battery. As a result, the thermal powergenerated that leaks out of at least a portion of the ducts, conduits,or other mechanisms that direct a conditioned working fluid, often stillcan be at least partially utilized. Thus, in certain embodiments, theconditioning surfaces such as ducts, tubes, etc. are positionedgenerally toward the working fluid, battery, or volume to be cooled, andthe heat rejection side generally away from the conditioned surfaces andarea.

FIG. 7 illustrates an example battery thermal management system 700 thatincludes at least one conduit 760 (e.g. fluid circuit) in accordancewith certain embodiments described herein. The battery thermalmanagement system 700 includes at least one battery 702 a-d and at leastone thermoelectric device 704 in thermal communication with the at leastone battery 702 a-d. The battery thermal management system 700 includesat least one flow control device 740 such as a fluid pump. The at leastone flow control device 740 circulates the working fluid through the atleast one conduit 760. In some embodiments, the working fluid isre-circulated through the at least one conduit 760. The working fluidmay flow into thermal communication with the at least one thermoelectricdevice 704, and the working fluid may flow away from being in thermalcommunication with the at least one thermoelectric device 704. Forexample, at least one heat exchanger 726 may be in thermal communicationwith the at least one thermoelectric device 704. The working fluid mayflow into thermal communication with the at least one heat exchanger 726and the working fluid may flow away from being in thermal communicationwith the at least one heat exchanger 726. The same working fluid mayflow into and away from being in thermal communication with the at leastone thermoelectric device 704 more than once. For example, the at leastone conduit 760 can be a fluid loop.

In certain embodiments, the battery thermal management system 700includes a fluid reservoir or source 750 fluidly coupled with the atleast one conduit 760. The fluid reservoir or source 750 may heat orcool the working fluid. For example, the fluid reservoir or source 750can be connected to other sources of heat such as an engine powertrainfluid to provide further heat to the at least one battery 702 a-d. Inanother example, the fluid reservoir or source 750 can include aradiator such as a vehicle chassis or an auxiliary radiator to rejectheat from the at least one battery 702 a-d through the at least one TEdevice 704.

The working fluid can be any type of fluid such as liquid, gas, ormultipurpose solid-liquid convection medium. In certain embodiments, theworking fluid comprises a mixture of water and glycol. A liquid workingfluid may have a greater thermal capacity than a gas working fluid,which can result in greater efficiency for the TE device 704. Inparticular, many heat exchangers with fins, etc. have a higher thermalcoefficient of performance or a higher heat transfer rate with theworking fluid when the working fluid is a liquid than when the workingfluid is a gas (e.g., air). A higher thermal coefficient of performancecan reduce the temperature drop across the interface between the workingfluid and the heat exchanger 726. Thus, the total temperature dropbetween the TE device 704 and the working fluid can be reduced. A lowertemperature drop can result in higher efficiency for the TE device 704and/or higher temperature differential across the TE device 704.

The thermal output of a BTMS may be varied to accommodate variousconditions, including operation in extreme environments. FIG. 5 is aschematic circuit diagram of an example thermal management system 500comprising a plurality of TE devices configured to change thermal poweroutput by changing the electrical configuration of the TE devices inaccordance with certain embodiments described herein. For example, underextreme ambient heat (or cold), it may be desirable to increase thecurrent through the TE devices to increase cooling (or heating) thermalpower output. The TE devices can be TE elements, TE assemblies, or TEmodules.

In certain embodiments, at battery thermal management system 500includes at least one battery and a plurality of thermoelectricassemblies 502 a, 502 b in thermal communication with the at least onebattery. Each thermoelectric assembly 502 a, 502 b includes a pluralityof thermoelectric devices. A first thermoelectric assembly 502 a of theplurality of thermoelectric assemblies is in electrical communicationwith a second thermoelectric assembly 502 b of the plurality ofthermoelectric assemblies. A circuit 506 is in electrical communicationwith the first thermoelectric assembly 502 a and the secondthermoelectric assembly 502 b. The circuit 506 can be configured to beselectively switchable to place the first thermoelectric assembly 502 aand the second thermoelectric assembly 502 b either in series electricalcommunication or parallel electrical communication with one another.

In some embodiments, at least some of the plurality of thermoelectricelements of the first thermoelectric assembly 502 a can be in serieselectrical communication and/or in parallel electrical communicationwith one another, and at least some of the plurality of thermoelectricelements of the second thermoelectric assembly 502 b can be in serieselectrical communication and/or parallel electrical communication withone another. For example, the first thermoelectric assembly 502 a caninclude a first plurality of TE groups 504 a, 504 b, and the secondthermoelectric assembly 502 b can include a second plurality of TEgroups 504 c, 504 d. As illustrated in FIG. 5, a first TE group 504 a ofTE devices are in parallel electrical communication with one another, asecond TE group 504 b of TE devices are in parallel electricalcommunication with one another, a third TE group 504 c of TE devices arein parallel electrical communication with one another, and a fourth TEgroup 504 d of TE devices are in parallel electrical communication withone another. The first TE group 504 a is in parallel electricalcommunication with the second TE group 504 b, and the third group 504 cis in parallel electrical communication with the fourth TE group 504 d.Similar features as discussed with regard to FIG. 1 can be included withcertain embodiments that include a circuit 506 that can be configured tobe selectively switchable to place the first thermoelectric assembly 502a and the second thermoelectric assembly 502 b either in serieselectrical communication or parallel electrical communication with oneanother.

The solid lines in the circuit 506 of FIG. 5 illustrate a first circuitposition wherein the first TE group 504 a, the second TE group 504 b,the third TE group 504 c, and the fourth TE group 504 d are in serieselectrical communication with one another. The dotted lines in thecircuit 506 of FIG. 5 illustrate a second circuit position wherein thefirst TE group 504 a is in series electrical communication with thesecond TE group 504 b, the third TE group 504 c is in series electricalcommunication with the fourth TE group 504 d, and the firstthermoelectric assembly 502 a (e.g., the first TE group 504 a and thesecond TE group 504 b) is in parallel electrical communication with thesecond thermoelectric assembly 502 b (e.g., the third TE group 504 c andthe second TE group 504 d).

In certain embodiments, a method of thermally managing a battery system500 includes providing a battery system including at least one batteryand a plurality of thermoelectric assemblies 502 a, 502 b in thermalcommunication with the at least one battery. The method further includesmeasuring at least one parameter of the battery system and switching, inresponse to the at least one parameter, a first thermoelectric assembly502 a of the plurality of thermoelectric assemblies between being inparallel or series electrical communication with a second thermoelectricassembly 502 b of the plurality of thermoelectric assemblies. The atleast one parameter can, for example, include temperature of the atleast one battery and/or the battery system. Additional parameters arediscussed in the following sections.

In some embodiments, the plurality of thermoelectric assemblies areselectively operable to either heat or cool the at least one battery.The circuit 506 may also be selectively switchable to adjust currentflow through the first thermoelectric assembly 502 a and the secondthermoelectric assembly 502 b. Furthermore, voltage of the circuit 502can be altered to cause more or less current to flow through the TEdevices in order to modify heat pumping capacity of the TE devices. Theperformance of the BTMS can be altered by, for example, altering fanand/or pump operation to change working fluid flow conditions such asflow rate and/or flow paths. The BTMS can further include a controllerto control the circuit 502, flow control devices, etc. of the BTMS. Thecontroller may be integrated with the BTMS or may be an externalcontroller.

Battery thermal management systems with monitoring systems

Thermal management can be important to the proper operation and life ofa battery or battery array, so monitoring temperatures and otherparameters to determine the state of operation of the BTMS can beadvantageous. Several conditions can also be monitored simultaneouslyand/or periodically or at various times to assure proper function andaddress operational discrepancies. Monitoring sensors and devices can beincorporated into the TE devices, fans and/or pumps the electricalcircuitry and other parts of the system to provide useful information.FIG. 6 illustrates examples of a plurality of monitoring systems 630 a-dand their locations in a BTMS 600 in accordance with certain embodimentsdescribed herein.

A TE device 604 can include one or more monitoring systems 630 a-dincluding TE device monitoring systems 630 a, battery monitoring systems630 b, working fluid monitoring systems 630 c, and flow control devicemonitoring systems 630 d that can measure at least one parameter. Themonitoring systems 630 a-d can be integrated within, on a surface of,neighboring, or within proximity to measure the at least one parameterof the TE device 604, battery 602 a-d, working fluid, flow controldevice 612, etc. For example, components such as fans, circuit elements,battery parts, batteries, components of a battery, battery arrays and/orBTMS can include monitoring systems 630 a-d.

A monitoring system 630 a-d can include one or more temperature sensors.Temperature sensors can include thermistors, positive temperaturecoefficient-thermal cutoffs, thermocouples and other temperature sensingand temperature activated devices. Temperatures that can be monitoredcan include, for example, working fluid, inlet fluid temperatures,conditioned fluid temperatures, temperature differentials between fluidinlets and outlets, temperature between the conditioning side and theheat rejection side, fluid control device (e.g., pump or fan)temperatures. Furthermore, multiple measurements at several locationsand any other combination of temperature measurements may be made.

In addition to temperature, fluid control device speeds, fluid controldevice voltages and/or currents, fluid flow rates at one or multiplelocations, emissions of fluids from the battery, battery array or anyother device, fluid velocities, battery voltages and/or currents,battery or battery dimensions and/or dimensional change can bemonitored. Furthermore, at least one monitoring system can includecircuit sensors to monitor electrical communication of circuits and/orTE devices 604.

Monitoring systems can also provide a signal or be in communication witha control device. In some embodiments, the control device may measurethe at least one parameter that is monitored, and the control devicemay, in response to the at least one parameter, cause at least onecomponent of the BTMS to change. For example, the control device mayapply an algorithm to the measured parameter to determine what response,if any, the control device may apply to a component of the BTMS. Controldevices can include devices that acquire sensor data, performcalculations based on the sensor data, and cause at least one componentof the BTMS to change such as valves, blower speed controllers and otherdevices to actuate or reduce/increase flow rate, etc., and parametriccontrollers.

In addition, at least one parameter (e.g., a signal) can be monitored todetermine the exposure the battery, battery array or BTMS may haveexperienced and any other operating history of the BTMS that may beuseful. The monitoring can be done for warranty, determining chargecycle (e.g., optimizing speed of charge), state of operation, safety,optimizing performance, increasing longevity, establishing operationalhistory, indicating failure, modifying battery charge schedules based onmeasured values, indicating impending degradation of performance and anyother diagnostic measurements.

Battery thermal management systems with additional features

In addition to the components, sensors, functions, etc. discussed above,the BTMS may contain control, communication, computational, storageand/or processing capabilities to act upon the information collected bycomponents of the BTMS and/or other systems in communication with theBTMS and communicate results of information processed by the BTMS and/orother systems. Thus, the BTMS may contain electronic signal processinghardware, input/output devices, permanent recording hardware or anyother useful electronic or other signal processing equipment. The systemmay have the capacity to take actions, send signals, receive signals,store information, perform logic functions, control temperatures, fanand/or pump, TE, and any other subsystem function, modify operationand/or perform any other function to manage battery or battery arrayoperation.

Various embodiments have been described above. Although the inventionhas been described with reference to these specific embodiments, thedescriptions are intended to be illustrative and are not intended to belimiting. Various modifications and applications may occur to thoseskilled in the art without departing from the true spirit and scope ofthe invention as defined in the appended claims.

1. A battery thermal management system comprising: at least one battery;at least one thermoelectric device in thermal communication with the atleast one battery; at least one first conduit comprising at least oneinlet configured to allow a first working fluid to enter and flow intothe at least one first conduit and into thermal communication with theat least one thermoelectric device, the at least one first conduitcomprising at least one outlet configured to allow the first workingfluid to exit and flow from the at least one first conduit and away frombeing in thermal communication with the at least one thermoelectricdevice; at least one first flow control device which directs the firstworking fluid through the at least one inlet of the at least one firstconduit; at least one second flow control device which directs the firstworking fluid through the at least one outlet of the at least one firstconduit; and wherein the at least one first flow control device and theat least one second flow control device are each separately operablefrom one another.
 2. The battery thermal management system of claim 1,wherein the first flow control device comprises a fan.
 3. The batterythermal management system of claim 1, wherein the first flow controldevice comprises a pump.
 4. The battery thermal management system ofclaim 1, wherein the at least one first control device is positioned atan entrance of the at least one inlet and the at least one secondcontrol device is positioned at an exit of the at least one outlet. 5.The battery thermal management system of claim 1, wherein the at leastone first control device is configured to push the first working fluidthrough the at least one inlet and the at least one second controldevice is configured to pull the first working fluid through the atleast one outlet.
 6. The battery thermal management system of claim 1,further comprising a flow path for the first working fluid in which thefirst working fluid is in thermal communication with the at least onebattery.
 7. The battery thermal management system of claim 6, whereinthe flow path receives the first working fluid from the at least oneoutlet.
 8. The battery thermal management system of claim 1, furthercomprising: at least one second conduit comprising at least one inletconfigured to allow a second working fluid to enter and flow into the atleast one second conduit and into thermal communication with the atleast one thermoelectric device, the at least one second conduitcomprising at least one outlet configured to allow the second workingfluid to exit and flow from the at least one second conduit and awayfrom being in thermal communication with the at least one thermoelectricdevice; at least one third flow control device which directs the secondworking fluid through the at least one inlet of the at least one secondconduit; at least one fourth flow control device which directs thesecond working fluid through the at least one outlet of the at least onesecond conduit; and wherein the at least third first flow control deviceand the at least one fourth flow control device are each separatelyoperable from one another.
 9. The battery thermal management system ofclaim 1, wherein the at least one first flow control device comprises atleast two first flow control devices.
 10. The battery thermal managementsystem of claim 9, further comprising at least one divider portion thatis selectively positionable to block the first working fluid fromflowing between the at least one first fluid conduit and a selected oneof the at least two first flow control devices, wherein each of the atleast two first flow control devices are each separately operable fromone another.
 11. The battery thermal management system of claim 1,wherein the working fluid is re-circulated through the at least oneconduit.
 12. The battery thermal management system of claim 1, furthercomprising a fluid reservoir or source fluidly coupled with the at leastone conduit.
 13. The battery thermal management system of claim 12,wherein the fluid reservoir or source comprises an engine powertrainfluid.
 14. The battery thermal management system of claim 12, whereinthe fluid reservoir or source comprises a radiator.
 15. The batterythermal management system of claim 1, wherein the first working fluid issubstantially thermally isolated from the at least one battery.
 16. Thebattery thermal management system of claim 1, wherein the plurality ofthermoelectric assemblies are selectively operable to either heat orcool the at least one battery.
 17. A method of thermally managing abattery system, comprising: transferring heat between at least onebattery and at least one thermoelectric device; flowing a working fluidthrough a fluid conduit in thermal communication with the at least onethermoelectric device; operating at least one first flow control deviceto direct the working fluid to be in thermal communication with the atleast one thermoelectric device; and operating at least one second flowcontrol device separately from the operating of the at least one firstflow control device to direct the working fluid away from being inthermal communication with the at least one thermoelectric device.
 18. Abattery thermal management system comprising: at least one battery; atleast one thermoelectric device in thermal communication with the atleast one battery; at least one fluid conduit configured to allow aworking fluid to flow therein and to transfer the working fluid intobeing in thermal communication with the at least one thermoelectricdevice or away from being in thermal communication with the at least onethermoelectric device; at least one first flow control device whichdirects the working fluid through the at least one fluid conduit; atleast one second flow control device which directs the working fluidthrough the at least one fluid conduit, wherein the at least one firstflow control device and the at least one second flow control device areeach separately operable from one another; and at least one dividerportion that is selectively positionable to block the working fluid fromflowing between the at least one fluid conduit and a selected one of theat least one first flow control device and the at least one second flowcontrol device.
 19. The battery thermal management system of claim 18,wherein the at least one divider portion is positionable in multiplepositions comprising: a first position permitting the working fluid toflow between the at least one fluid conduit and the at least one firstflow control device and permitting the working fluid to flow between theat least one fluid conduit and the at least one second flow controldevice; a second position permitting the working fluid to flow betweenthe at least one fluid conduit and the at least one first flow controldevice and blocking the working fluid from flowing between the at leastone fluid conduit and the at least one second flow control device; and athird position blocking the working fluid from flowing between the atleast one fluid conduit and the at least one first flow control deviceand permitting the working fluid to flow between the at least one fluidconduit and the at least one second flow control device.
 20. The batterythermal management system of claim 18, wherein the at least one dividerportion comprises a flapper valve.